Automatic switching device



April 14,1925; 1,533,188

A. D. HARGAN AUTOMATIC SWITCHING DEVICE Filed Oct. 8, 1921 Patented Apr.14, 1925.

UNITED STATES PATENT OFFICE.

AUGUSTUS D. HARGAN, OF BAYONNE, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRICCOMPANY, INCORPORATED, 013 NEW YORK, N. Y., A CORPORATION OF NEW YORK.

AUTOMATIC swrrcrrme DEVICE.

Applicationfiled October 8, 1921. Serial No. 506,315.

To (/JZ whom it may concern:

Beit known that I. AUGUSTUS D. HAR- (am, a citizen of the United States,residing at. Bayonne, in the county of Hudson, State of New Jersey, haveinvented certain new and useful Improvements in Automatic SwitchingDevices, of which the following is a full, clear, concise, and exactdescription.

This invention relates to telephony, and particularly to automaticswitching devices, for example rotary stepping switches having feederbrushes, the objects being to improve the form of the feeder brusheswhereby a positive connection is established and maintainedtherethrough, wear is reduced to a minimum, and the operating load onthe motor magnet is rendered continuously uniform.

A feature of the invention is a bifurcated feeder brush having turneddown end portions whereby a positive connection is established andmaintained, this brush being so designed at the point where it emergesfrom the contact bank that the associated switch brush will mount it ata different point in its travel than where it mounts the oppositelypositioned switch contact.

In the drawings Fig. 1 shows a top view of a switch bank with one of therotor brushes cut away to illustrate the manner in which the feederbrush makes contact with the hub of the rotor brushes. A stepping magnetwith its pawl and cooperating ratchet associated with the brushes areshown. Fig. 2 is a perspective View showing the assembly of the rotorbrush spindle and the manner in which the feeder brushes are mounted.

The organization of the stepping switch comprises a bank of contacts 1secured in a frame 2. Centrally disposed to the bank of contacts is aspindle 3 having mounted on it a number of sets of brushes 4. Mounted inthe frame 2 is a feeder brush 5 extending into the field of the rotorbrushes. This feeder brush has a bifurcated end 6 with turned downcontacting portions 7 at the end of each prong formed at an angle tocenter line of the brush for the purpose of presenting as wide acontacting surface to the rotor brush as possible and thus avoid cuttinga ring in the hub of the rotor brush. These turned down contactingportions rest on the hub of the lower one of the two brushes 4 forming aset. The upper brush 4 is connected to the lower brush 4 by means of aconducting spacer S and the first set of brushes 4 is insulated from thesecond set of brushes 4 by an insulating spacer 9.

The means for rotating the brush comprise a magnet 10- having anarmature- 11 on which is mounted a spring 12 having a pawl 13 securedthereto. When the magnet 10 is energized, the pawl 13 is propelled tothe left and drops into the next tooth of the ratchet 14. Upon thedeenergiza-tion of the magnet the spring 15 moves the armature 11 backto its normal position and causes the brushes 4 to rotate from onecontact to the next. A spring 16 is used as a holding pawl to preventany backward motion of the brushes 4.

The feeder brush 5 at the point 17 where it emerges from the contactbank is somewhat wider than a contact so that the end 18 of the brushwill ride up on the feeder brush before the end 19 rides up on thecontact at the opposite end of the bank, thus preventing the spring 15from being required to overcome a double amount of work at thisparticular time.

What is claimed is:

1. A stepping switch comprising a bank of passive contacts, a pluralityof cooperating brushes, a corresponding plurality of feeder brushessecured in said bank for making continuous contact with said brushesthroughout their travel, each said feeder brush being wider than saidcontacts at the point where it emerges from the said bank, whereby saidbrushes mount said feeder brushes at a different point in their travelthan where they mount said contacts.

2. A stepping switch comprising a bank of contacts disposed over half acircle, a plurality of cooperating brushes, each said brush having twoopposed contacting points whereby as one point leaves the last contactof said bank the opposed point mounts the first contact of said bank, acorresponding said brushes mounts said feeder brushes bcplurality offeeder brushes secured in said fore the opposed contacting point mountsbank for making continuous contact with said contacts.

said brushes throughout their travel, each In Witness whereof, Ihereunto subscribe said'feeder brush being Wider than said conmy namethis 6th day of October A. 1)., tacts at the point Where it emerges from1921.

said bank whereby one contacting point of AUGUSTUS D. HARGAN.

